30913920 has 128 divisors (see below), whose sum is σ = 109548000. Its totient is φ = 8239104.

The previous prime is 30913919. The next prime is 30913951. The reversal of 30913920 is 2931903.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16386 + ... + 18174.

Almost surely, 2^30913920 is an apocalyptic number.

30913920 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 30913920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (54774000).

30913920 is an abundant number, since it is smaller than the sum of its proper divisors (78634080).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

30913920 is a wasteful number, since it uses less digits than its factorization.

30913920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1817 (or 1799 counting only the distinct ones).

The product of its (nonzero) digits is 1458, while the sum is 27.

The square root of 30913920 is about 5560.0287769039. The cubic root of 30913920 is about 313.8470322041.

The spelling of 30913920 in words is "thirty million, nine hundred thirteen thousand, nine hundred twenty".